Instructions for migration to tagulous are wrong

[radiac]

It looks like the instructions for migrating to tagulous don't work correctly - in step 2 I don't think taggit (or tagging) is going to work in the data migration. I can't test this at the moment, but if that's the case we need to collect the tags directly, using the generic relations.

I had thought I'd tested that bit thoroughly at one point, so not sure how that got through - but because it's only in the docs there are no automated tests. Sorry! It should be possible to add some though.

I'm travelling at the moment, so it may take a couple of weeks for me to fix (patches welcome of course) - I'll update the docs in the meantime.